Grenade launchers fire all kinds of grenade cartridges. Some are chemical, which dispense tear gas or nausea gas. Others fire flares for signalling, marking rounds with smoke, phosphorus for lighting fires, and regular high explosive for anti-personnel and armor piercing purposes.
Development of magazine fed grenade launchers has been hindered by the short, large diameter, blunt nosed cartridges used in grenade launchers. Gun mechanisms used with magazine fed grenade launchers have been necessarily long, or complex in order to provide reliable ramping of the grenade cartridge toward the chamber. Ramping, in prior art gun mechanisms is the movement of the cartridge on an angled surface provided in the weapon mechanism for guiding the cartridge from its position in a cartridge magazine into the chamber of the weapon. Most prior mechanisms provide marginal round control, permitting significant random movement of the cartridge during chambering because there is a portion of the chambering event in which neither the magazine, nor the ramp nor, nor the chamber closely guides the cartridge. The chambering ramp also provides opportunity for the nose of the projectile, or base of the cartridge case to escape from the desired path during attempting chambering, causing a weapon stoppage.